# Option Delta

The Option Delta indicator uses the Black-Scholes model formula. This mathematical equation estimates the theoretical value of derivatives other investment instruments, taking into account the impact of time and other risk factors. Check here for more info about the Black-Scholes indicator.

## Description

Delta is the ratio that compares the change in the price of an asset, usually marketable securities, to the corresponding change in the price of its derivative.

The Option Delta indicator plots the option's Greek Delta risk value which is based on the asset's price series. The indicator requires the option data to be specified in the Input values (expiration month, expiration year, strike price, etc). Delta shows the expected risk of option price movement which is based on price changes in the underlying asset.

When applied to a chart, this indicator displays one plot in a separate subchart from the main data series.

## Default Inputs

**ExpMonth_MM( 0 )** sets the month (1-12) the option expires.

**ExpYear_YYYY( 0 )** sets the year the option expires.

**StrikePr( 0 )** sets the option strike price.

**Rate100( 0 )** sets the risk free interest rate.

**Volty100( 0 )** sets the annualized volatility value.

**PutCall( put )** sets the option type (Put=2, Call=3), put by default.